


can't pull yourself up by a paradox

by TheseusInTheMaze



Category: Doctor Who (2005)
Genre: Established Relationship, F/F, Out of Order Meeting, Puzzles, Time Travel, alien planets, bootstrap paradox
Language: English
Status: Completed
Published: 2020-11-22
Updated: 2020-11-22
Packaged: 2021-03-09 23:08:38
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 10,551
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27663838
Author URL: https://archiveofourown.org/users/TheseusInTheMaze/pseuds/TheseusInTheMaze
Summary: River gives the Doctor a gift, with a few instructions. The Doctor does her best to follow them.
Relationships: Thirteenth Doctor/River Song
Comments: 8
Kudos: 29
Collections: Heart Attack Exchange 2020





	can't pull yourself up by a paradox

**Author's Note:**

  * For [FictionPenned](https://archiveofourown.org/users/FictionPenned/gifts).



> This fic was an absolute delight to write, and I hope you enjoy reading it as much as I enjoyed writing it!

"Y'know," said a familiar voice, "when people are trying to pick a lock in a prison, it's to get _out_ of a cell, not into it." 

The Doctor jumped, looked over her shoulder. She was crouched down, lockpicks in hand, and she was fiddling with the door to the cell that all her _stuff_ was locked in. The name popped out of her mouth before she had a chance to catch herself. "River?" 

River Song, resplendent in an emerald green dress and a trench coat belted around the waist, looked down at the Doctor, and she had an eyebrow cocked. "Where do I know you from?"

"Well," said the Doctor, and she cleared her throat, standing up and brushing herself off. "Well," she said again, as her mind raced, trying to find a reason to know River. "Well, I mean, everyone's heard of River Song. I went to one of your lectures once. I think it were called, uh..." She screwed her face up, tried to remember the lecture itself. She mostly remembered the seafood restaurant they'd gone to afterwards, and foiling a plot to kidnap the princess of the eel people. 

"Um?" River was tapping one foot - she was wearing a pair of very red high heels, and the leather was very shiny in the dim hallway.

The Doctor sat back on her haunches, trying to get her thoughts in order. "Yes! I remember now! Driving Home the Point: Large Scale Symbolic Messaging in 21st Century Material Culture!" 

River smiled, and it was the familiar smile that always sent a cloud of butterflies through the Doctor's stomach. How had she managed to marry such a beautiful woman? The corners of her eyes crinkled up, and her nose wrinkled. "That one was a hit," she agreed. "Especially when we ended up trying to figure out which crop circle was the real one and which was the fake one."

"Yeah, and then it turned out that all of them were fake," the Doctor agreed. She stretched, her hands over her head and her back arching. The new body didn't have the back problems that her previous ones had dealt with, but hunching over like that was never _comfortable_. "Well, they were genuine crop circles, but they weren't caused by any kind of extraterrestrial life." _Apart from the time I made one, but I used a golf cart, so I'm not sure if that counts._

"Humans tend to look very hard for meaning wherever they can find it," said River. "That lock giving you much trouble?"

"Didn't pack the right kind of lock pick," said the Doctor, and she was aware that she was pouting a bit. "Thought that it'd be digital, since all the other locks are around here, but seems like they chucked my kit into one of the older cells, so I had to do it a bit more old school." She huffed her greasy hair out of her face, and she wrinkled her nose. "Only it turns out that the locks around here are made of some kind of super dense steel, which means that it's exceptionally hard for me to pick it with the aluminium that I filched from the canteen."

"Let me help you with that," said River, and she offered the Doctor a hand up. When they were standing face to face, River was a little bit taller in her heels, and the Doctor was acutely aware of her greasy hair and stained prison boiler suit. "I've got some experience with these. "

River's hand was as familiar as ever - soft with lotion, with callouses where she held her trowel. Their fingers laced together for a moment, and the Doctor glanced into River's eyes, then looked back down, letting River's hand go. She was blushing, all the way up to her ears, but she didn't want to think about that too hard right then. They shouldn't have been meeting up like this, not when their timelines were already tangled up like a basket of yarn after a litter of kittens had been at it.

But everything was just so _hard_ , so confusing, so lonely. There was a deep, almost painful comfort in finding a familiar face, even if the face didn't recognize her own. And she knew River didn't recognize her, River _never_ recognized her with a new face, and it'd be a bad start for her to see who the Doctor would be, after her.

... sometimes the whole time travel business gave the Doctor some truly glorious headaches. 

River crouched down in front of the door, and she frowned at it, her brow furrowing. "They really need to upgrade," she said, as if she was talking to herself. "This is just embarrassing."

"Oi," the Doctor said, faintly offended in spite of herself. 

River took a pin out of her hair, and she shot a glance over at the Doctor, flashing a smile. "No offense," she added, and the grin she flashed was cheeky. "I just have a lot of experience picking locks, what with one thing and another."

"Are you a cat burglar?" Was that something someone would ask someone else who said they had a lot of experience picking locks? She was flying a little blind here. "Must be exciting." 

"I'm an archaeologist," said River, and there was a click, "but you know how it is. Sometimes... Well, sometimes you have to dig a little more creatively. Using different tools." She stood up straight, and she brushed off her knees, then opened the door. "There you go."

"So what brings you to, uh... here?" The Doctor looked around the big, empty hallway with its flickering lights. "You don't look dressed for prison." She tugged on her own red boiler suit, making a face.

"Oh, I'm just stopping by," said River, and she gave the Doctor a sunny smile. "I suspect you're about to be leaving soon."

"Definitely," the Doctor said, nodding emphatically. "Not exactly my kinda scene, this." She made her way into the cell, which had been repurposed into a storage room. And there was her coat, her trousers, her shirt, all in a heap. 

"You look like the type who's been in a prison cell a time or two," River said, and her eyes were moving up and down the Doctor's form. "Although how'd you get out, if you have trouble with locks?"

The Doctor cleared her throat, and turned her back on River. "I don't usually have trouble with locks," she said, and she tried to sound a little bit less defensive. "The newer ones are easier to deal with. Usually you just need to reprogram them, maybe give 'em a good thump." She unbuttoned her boiler suit and shrugged out of it, grabbing her two t-shirts. "Love me a good lock, like a nice puzzle. Who doesn't love a puzzle, really?" 

River was quiet, and the Doctor glanced over her shoulder. She wasn't sure if she was relieved or disappointed to see River not even watching as she rifled through the great crates spread out around the small room. 

She pulled her trousers on, traded her prison slippers for her boots, and fastened up her braces. After River failed to respond, she tried again. “So what brings you to this neck of the woods? Well space station. This… arm of the space station. Doesn’t flow as well, does it?” She shrugged into her coat, and some of the tension left her shoulders. She shoved her hands into her pockets, and found her sonic, her psychic paper, her sunglasses, her lucky pen. “Doesn’t seem to be your type of place, really. Classy woman like you, you look too nice for all this industrial whatnot.” 

“Had to pick something up,” said River. “Person I’m married to asked me to get them something.” 

“Did I… know that?” The Doctor gave herself some credit for the save. “No, obviously, that’s why I asked you.” She cleared her throat. “Sorry. Bit of a babbler when I’m nervous, and who doesn’t get nervous when they’re in the middle of a prison escape?”

“I tend to find them calming,” River said, her tone reflective. “Not a lot of questions - you know where you’re coming from, you know your end goal is to get out… fairly straightforward, all things considered.” 

“Straightforward can be nice,” the Doctor agreed. _I know I can track the TARDIS. I just need to figure out where I’m tracking it to. And she doesn’t know I’m the Doctor, and the TARDIS would be a dead giveaway._ “Do you break out of prison often?”

“Fairly often,” said River. She still sounded distracted. “Don’t have to deal with the Judoon too often, thankfully. Those rhinos are remarkably pigheaded.” She sighed, and then she gave the Doctor another once over. “So those are your clothes?”

“They are indeed,” the Doctor said cheerfully, hooking her fingers into her pockets and giving a little pose. “Much more stylish than the prison suit, I’ll tell ya that!”

River raised an eyebrow, and then she turned around and went back to rummaging. 

“What are you lookin’ for?” The Doctor tried to keep her tone casual. She wasn’t sure why she was stung by the dismissal, and yet. 

“I know it’s here,” said River, her tone distracted. “Gave me the exact coordinates, anyway.”

“D’you need help looking?” The Doctor offered, and she sidled a little closer. She could smell River’s perfume, and it was making her eyes mist up. 

“Nope,” said River, and then she seemed to find it, because she stood up, triumphantly brandishing… a box?” “Aha!” 

“What is it?” The Doctor frowned at the dark wooden box. It looked about the size of a tin of tea, 

“It’s a puzzle box,” River explained. “It was confiscated off of me, the last time I was here.”

“So you’ve been jailed here before, then?” As far as the Doctor knew, River had always been kept in Stormcage, when she felt like staying in prison. 

“Oh, you know how it is,” River said, and she was carefully looking over the puzzle box. “If those lumbering idiots damaged it…” She did… something complicated, and the whole thing opened up like an accordion, brightly colored panels flashing like beetles. There was music playing, music made of different sorts of instruments the Doctor couldn’t identify, slightly tinny. It had a handmade look to it, as if the person who created it had loved and pondered over every step of the process. It had definitely been made by an expert at their craft. 

“Wow,” the Doctor said, awed beyond words.

“Excellent,” said River, and she closed the puzzle again, before the Doctor had a chance to properly examine it. The music had gone silent, and it was a plain, dark wooden box again.

Then she tossed it at the Doctor, and she smiled. “Why don’t you solve that for me, sweetie?” She smiled at the Doctor, with all her teeth, and the Doctor flushed. 

“Bit forward of ya, talkin’ to me like that,” the Doctor said, although her heart wasn’t in it.

“We both know that I know who you are,” River said, and her tone was affectionate even as she said it. She came closer, patting the Doctor on the cheek. 

The Doctor sighed, and she covered River’s hand with her own. “If you knew, why didn’t you say anything?” The Doctor hated how petulant she sounded, but couldn’t seem to stop. 

“I wanted to see how long you could keep it up,” said River, and she grinned. She pressed closer, and she kissed the Doctor on the mouth, a soft little peck on the lips. “Spoilers,” she said, and she pressed the puzzle box into the Doctor’s hands. “Solve it for me and give it back,” she told the doctor, and then she was taking a step back and pressing a button on her vortex manipulator. 

The vortex manipulator beeped, and then River was gone. The Doctor was alone in the room, still holding the small puzzle box. “Well,” the Doctor said into the empty room, and she looked down at the box. “Shouldn’t be too difficult.” 

* * *

Finding her TARDIS took almost no time at all - she would have considered it a bit suspicious, except the Judoon… well. They were that thick. Once she hit the Time Vortex, she sighed, leaning into the console. Then it was just a matter of fiddling with the shields to keep the Judoon (or anyone else) from coming in uninvited.

And then it was just her and the puzzle box. 

The Doctor scanned the little wooden box, and found it to be made of... a lot of things, honestly. It wasn’t actually made of wood - the casing was made to look like wood, but was some kind of very advanced carbon. And it was covered in a whole myriad of… stuff. Traces of different minerals, wood, pollen. The surface of it was smooth and glossy, as if it had been varnished, but when she ran her fingers along it she could feel indentations where things folded or hinged away. Couldn't figure out any way to get it _open_ , though, and while she could, in theory, use the sonic, that would be cheating, right?

It was _awfully_ tempting, as the little box stood there on the console, innocuously reflecting the golden light. 

"Let's see," the Doctor said absently, squinting at the readouts. "Looks like these trace elements are from..." More squinting, then a low whistle. "Karabrr?" 

Karabrr, the ice asteroid turned pleasure resort. Sort of like one of those ski resorts up in the Swiss Alps, only with more variety in their hot chocolate supply, and ice climbing versus skiing. 

It had been a while since she'd been back - had she taken Amy and Rory? No, it had been with Bill, because they'd ended up having to stop a whole Situation involving crash landed Pyroviles, and then they'd watched one of the suns rise over the great mountain of ice, and Bill had taken a lot of pictures of rainbows. The ice had been specially manufactured (sort of), so that it all came in different temperatures. Really a marvel of modern (or antique, depending on what era the Doctor was standing in) terraforming. She hadn't had a chance to really have a good look at it, though. 

It'd be nice, to just go and admire the scenery, take in the wonder of good engineering. 

In theory.

It was never that simple, of course, but... well, a person could hope, right?

* * *

The puzzle box began to get warmer, as the Doctor wandered along the nature trails. When she went in certain directions, it began to get warmer, then cooler. "Is this what we're doing, then?" She asked the little wooden box.

Only one way to find out, really. 

She ended up going off the beaten path (not a surprise), her boots crunching through the slush. In retrospect, she probably should have worn longer trousers, since her shins were getting soaked, and so were her socks, but cold toes were livable. Wet socks were... less so, but she could breeze herself into one of the nearby fancy hotels and warm her toes by the fire without any trouble once she had the chance. And there would be a fire, these sorts of places always had big roaring fires and squishy armchairs. Probably marshmallows, too. 

The box in her hands was beginning to get warmer in her hands, like a cup of warm cocoa. The ice was slippery under her boots, and she had to be very careful as she walked. It was getting a tad precarious, as she made her way up one ridge. 

_Like that one fairy tale, about climbing a mountain of glass_ , she thought, her mittened hands wrapped around the smooth wood. _Although was that to fight a dragon? Or was there a prize? Maybe a dancing princess?_ Not that there would be any kind of dancing princess at the top of this ridiculous block of ice. She'd danced with enough princesses to know that it was a variable experience. Some trod on your toes, some had horrible halitosis, and some literally and figuratively swept you off your feet.

It helped that the ice she was walking on was warmer. The cold had begun to creep in through the soles of her shoes, and her cold toes curled in her damp socks as she took step after careful step. The puzzle box was getting warmer, fractionally, but she wasn't sure if anyone who didn't have her finely tuned Time Lord senses would have been able to tell. 

The incline was getting a little steeper, and she was having to be a little more careful. She ended up stuffing the box into the pocket of her trousers so that she could climb up a little more carefully. She dug her toes into the ice, and it was warm enough (but _solid_ enough, strangely) that she was able to hold on without her fingers going numb. 

"Warm ice," the Doctor murmured, as she scrabbled up towards the very top of the slope. "Who would've thought?"

When she was finally on the summit, she stood up and brushed her hands off, then pulled the puzzle box out again. It was warm enough that it was almost uncomfortable to the touch now, especially in comparison to the cold air. 

And there was another wall of ice, blue-green as the suns shone through it. 

"I hope I don't have to climb up that," she said out loud, looking from the smooth box to the great, terrifying wall. "I don't think I packed my crampons."

"Those shouldn't be necessary," said a familiar voice, and the Doctor's whole face was lighting up in a smile before she could stop herself. 

"River," the Doctor said, as her wife inched along a narrow ledge, then came out onto the more broad, flat area the Doctor was currently standing on. "What are you doing here?"

"Thought I'd stop by to admire the scenery," River said, and she gave the Doctor a smile. "I've got a fire going - come sit, we can warm our bones a bit."

"I think it's the stuff outside my bones what need warming," the Doctor said, but she followed after River, inching along the narrow little outcropping, then onto the wider, flatter area that a campfire was currently crackling away on. "Although really, can't complain. Isn't that cold, all things considered." 

River crouched down in front of the fire, holding her gloved hands out in front of her. They were fingerless, with the tops that would be mittens pulled back to her wrists by buttons, in a monstrous hot pink color. Her coat was a thick wool thing, the same shade of navy blue as the Earth sky right before it turned grey at sunrise. The piece de resistance was a knitted fuschia hat, topped with a screaming purple pom pom. 

"It's good to see you," River said, and then she indicated for the Doctor to come sit next to her.

The Doctor sat on the ground - the ice was warm, although not warm enough to be _comfy_ , exactly. She brought her knees up to her chest, and she watched the flames lick away at the logs. River must have brought her own wood, since there weren't any trees around here. 

"It's good to see you too," the Doctor said, and she squeezed River's hand when it was pressed into her own. She tried not to stare at the hat, but River caught her looking, and she smiled. 

"You made that for me, remember?" River took it off, patting the pompom fondly. “You said you wanted to use the last of this color, when we were staying in that one mining outpost for three months.” 

"I feel like I'd remember that," the Doctor said, indicating the bright pink. "Doesn't seem your usual style, I must say."

"Oh, it's not," River agreed, "but it does suit me, doesn't it?" She put the hat back on, pulling it over her ears, and the Doctor smiled at her slightly goofy expression

"So what brings _you_ here?" The Doctor said, and rubbing her hands together with the puzzle box still in her lap.

"Oh, you're still working on that, then?" River looked over at the puzzle box, and her face was bright. 

"So I'll be working on it in the future, then?" The Doctor tried not to think about her own time stream too much. "I'd have remembered running into you in the past."

"Spoilers," River said, and she winked. 

The Doctor wrinkled her nose, but she was grinning a bit in spite of herself. 

"Can I get any kind of hint?" The Doctor said, and her tone was only a little bit plaintive. "Just something to steer me in the right direction."

"I don't know," said River, and she looked as pleased as the cat who got the cream. "Is it as satisfying, knowing that you had my help to solve it?"

"You were the one who gave it to me," the Doctor reminded her. "Seems only sporting." 

"Well," said River, and she made a thoughtful face, staring up at the great wall of ice behind them, "I suppose I could give you a bit of a hint." 

"Yes?" The Doctor looked at her eagerly, the puzzle box warm in her hands. 

"Find where it matches," River said, and then she was rummaging around in her shoulder bag and taking out a thermos of what smelled like hot cocoa. "Would you like a cuppa, dear? It’s got marshmallows.” 

"Find where it matches," the Doctor said, and then she was grabbing the puzzle box again, and walking slowly towards the ice wall. She was beginning to get an idea of what she was expected to do, but... hm.

* * *

River, to her credit, was fairly patient as the Doctor descended down into her own mind to figure out the solution. It had turned into something like a _quest_ now, and the Doctor almost had the shape of what it was she was trying to access.

She had her bare palms against the ice, and she was moving them up and down along the ice wall. It was warm ice, but it seemed almost... layered. It got warmer in certain points, colder in others. Some of it was based on the sun, and she held the puzzle box in one hand and kept her sensitive fingertips against the wall of ice, moving frowning in concentration as she tried to find what she was looking for.

She found it. She even switched hands, to make sure that she was judging it correctly. It would have been easier with some kind of temperature readout, but she only had the sonic to do that, and it felt like cheating.

The Doctor pressed the side of the puzzle box against the one spot that the sun was shining through the ice, making it a few degrees warmer than the rest of the ice, the same temperature as the puzzle box. The puzzle box chimed like a little bell, and one of the compartments opened up, revealing a blue panel made of what looked like mother of pearl. 

"Oh," the Doctor said, her voice very quiet, and she ran the pad of her finger along the smooth surface. It chimed again, and the chime sent little vibrations through her fingernail. 

"That's very pretty," said River, and she was very close behind the Doctor. When had that happened? 

"It is, isn't it?" The Doctor tapped it, and it rang out again, sharp and clear as a bell. 

River's hand closed around the Doctor's, lacing their fingers together. The tips of her fingers were very cold against the backs of the Doctor's hands, and the soft fuzziness of her gloves caught on the calluses of the Doctor's palms. "Come warm your bones, darling," she said, and the look she shot the Doctor was so full of tenderness it made a lump from in the Doctor's throat.

She sat on the ice, which was just warm enough to not make her backside go numb. She held her wife's hand, listening to the chimes of the little puzzle box and watching the flames flicker. The sky began to turn a deep, dark violet as the suns began to set, and she let the heat from the fire (which was somehow not melting the ice, which was a fascinating thing she would have to investigate later) warm her to her bones.

* * *

Some time later, the Doctor sat in the TARDIS, her elbows on her thighs, and she stared at the puzzle box. The TARDIS had grown a little shelf for it to sit on, and it stayed in place even as the old ship rattled its way through the Time Vortex. 

"Yaz has a family do," the Doctor said out loud, staring off into the distance, "and Graham took Ryan on a holiday." She grinned to herself. "A busman's holiday!" 

There was nobody around to appreciate her joke, unfortunately. 

"I _could_ move forward in time a bit," she added, standing up and beginning to pace around the console room, "go get 'em afterwards. We _did_ have an established day we were gonna do stuff. But. Hm." She tapped her lip with her index finger, still staring fixedly at the puzzle box. "I want to know the next bit."

And she missed River, although she'd be loath to say it out loud. Both because admitting to those sorts of feelings out loud was always faintly embarrassing, and because then the TARDIS would hear her and then the TARDIS might bring her to River and that was against the spirit of the thing, wasn't it?

Then again, the TARDIS was already connected to her thoughts, so technically everything was sorta-kinda being heard by her sentient ship, but... well, it was like romance or flatulence. Didn't count 'til you said it out loud. 

"Just gonna take a quick look," the Doctor said, as if she was talking about peeking in on her Christmas presents, and not... whatever wild goose chase her wife had sent her, running through time and space. 

It was probably a bad idea. Who even _knew_ what it would do to the time stream? 

She drummed her fingers on her chin, staring unseeingly at the terminal. She already knew what she was going to do, but. 

Well. 

One little stop couldn't hurt, could it?

She flipped the switch on the TARDIS to scan a side of the puzzle, as she watched the golden light of the TARDIS reflected on the blue mother of pearl shine from the opened side of the puzzle. 

* * * 

The caverns of Iopika-7 were relatively pretty, as far as caverns full of crystals went. It was hard to have a cavern full of crystals _not_ be pretty, all things considered. Something in the mind of most living things found sparkly crystals attractive in an aesthetic sense. And then you got your crystalline lifeforms, that found sparkly crystals attractive in all the other senses, and really, the moral was, who didn't like a good crystal? 

But the _real_ draw of the Iopika-7 caverns were not the sight of the crystals, pretty thought they were. The caverns were kept in low lighting, to magnify the impact of what they could _actually_ do. 

Something about the Iopika crystals changed sound. Made some of them resonate and others twinkle. Singers came here to see what they could stretch their limits to, and music recorded here was said to be able to summon spirits themselves. 

There were traces of Iopika crystal on the puzzle box, and as soon as the TARDIS materialized in one of the little offshoots of the great underground cave network, the little box in her pocket began to vibrate. 

_Probably a sign I'm in the right place_ , the Doctor thought, taking it out and holding it up. The damn thing wasn't emitting any light, which might make it a little difficult to navigate the dim caverns, but she'd manage. She always did. 

* * *

The caverns were fairly quiet, after the echoes of the TARDIS had died down. The whole place was looked after by a trust, and the folks who came here had to get a permit. She'd made sure to come during one of the quieter times of year (no pun intended), and this was a fairly unused part of the cave system to begin with. She carried the small, vibrating box in front of her, and she stepped carefully, trying not to make too much noise. 

The ecosystem wasn't _delicate_ , per se (inasmuch as any ecosystem could be considered hardy, all those living things strung together like a loom that would unravel if even one thread was pulled out), but she still tried to keep to the path. She could see the glinting reflection of the cave crabs scuttling in the shadows, and the dim lights seemed to shake a little each time the crystals picked up the sounds of the Doctor's footsteps, which made the shadows dance. 

There were little sounds all around her - the small body sounds that come from living things in a space, the steady drip of water, the little scrapings as rock was disturbed. For all that she was probably the only sentient life for several kilometers out, she still didn't feel alone. It was a bit like being in the TARDIS, in its own way - the caves were almost alive, with all the things they had inside of them, and all the feelings people had poured into them. Her footsteps were like a heartbeat, and her own hearts seemed to be matching the beat, and echoing through the whole of the place. 

For all that she’d only been here once or twice before, it felt a little bit like coming home. She knew how it felt to be held in the guts of a thing that loved its inhabitants, and the familiarity was like a hug from a best mate. 

The puzzle box kept vibrating in her hand, buzzing quietly. It was a little bit like holding a jar full of bees, She held it in front of her, and she tried not to trip over her own feet as she wove through the quiet spaces with the puzzle box stretched out in front of her, like a new sort of geiger counter. It was beginning to buzz, very quietly, and the buzzing was echoing through the chambers. 

She stood in the middle of a small, dark cavern, and the crystals were on all sides. It was a bit like being on the inside of a geode. 

"Okay," the Doctor said, her voice quiet, as the little box hummed quietly in her hand, "I think I'm in the right place, but I'm not sure what to do... next."

There was a sound of displaced air, as matter suddenly appeared in a space where there hadn't been any matter, and it echoed strangely through the caverns. The Doctor squinted in the darkness to see... River? 

"Hello, sweetie," said the Doctor's wife, and she walked right up and kissed the Doctor on the mouth, an affectionate little peck. 

"River," the Doctor said, aware of how silly she sounded. The other woman was wearing comfortable clothing, as if she'd been lounging about in the park somewhere - she even had a sun hat tucked under her arm. 

"Oh, I see where we are in the timeline," River said, and she put her hand on the box as well. "Still working on it, then?"

"I must work on it a long time, if you've asked me twice, now," said the Doctor.

"Have I, then?" River looked interested. 

The Doctor wrinkled her nose. She knew that it was almost intrinsic to the nature of their relationship that they were always tripping over each other in the wrong direction, but... it still sometimes made her itch. 

"Spoilers," said the Doctor, and It was River's turn to wrinkle her nose.

"You know, as satisfying as it is to say, I think I sometimes forget how obnoxious it is to hear," she said, her tone thoughtful.

"And yet you keep saying it," the Doctor pointed out. 

Their voices were echoing back to them, distorted, and the box seemed to thrum a little harder at certain notes. The Doctor frowned down at it, the problem beginning to tick away in her mind, and then she arrived at a solution.

The Doctor sang a note, a little vocable "la". The box began to vibrate faster, and she held the note, as it echoed and distorted wildly through the echoing chamber. Then River joined in, harmonizing with her, their two voices twining together like a braid, and the box let out a chime, which melded into their own voices. Another side of the box opened, this side a bright, glossy purple that seemed to capture every little bit of light and reflect it back brighter. 

The echoes died away, and the Doctor looked at the puzzle, now blue and purple, bright and smooth under her fingers. 

"You really need to tell me where you found this," the Doctor said, faintly breathless. 

River's hand covered the Doctor's own. The puzzle box had stopped chiming, and it seemed to be picking up all the light in the room. "Spoilers," she said, and then she kissed the Doctor in the dim cavern, the light from the puzzle box reflecting off of the crystals all around them. 

* * *

Some time later, the Doctor stood by herself in her empty TARDIS, the puzzle box sitting on its little shelf as she fiddled with the wiring on the oxidizers. She was so engrossed in her work that she didn't actually notice that the TARDIS was trying to get her attention until it beeped at her and gave her a little electric shock through the wires she was stripping.

"Ouch," the Doctor said, shaking out her shocked fingers. "No need to shout, y'know. I _am_ paying attention." 

A disbelieving boop. 

"Sorry," the Doctor said, and she stroked the control panel. 

The puzzle box emitted a little chime, and the TARDIS beeped back. Another chime, another beep, and the Doctor paused, her hands shoved in her pockets. _Is it sentient? Nah, can't be sentient, I'd have been able to tell._ Maybe faintly telepathic circuitry? That was a thing that could happen sometimes, although it was fairly rare. And what would River even be doing with a telepathic puzzle box, anyway?

"I'd say she wouldn't do something so daft," the Doctor said reflectively, "but..." She took her hands out of her pockets, drummed them on the TARDIS console. "Where d'you want to go, old friend?"

One of the screens began to flash, speedily moving through a galaxy, towards a particular planet. "Perahk?" She frowned, as the TARDIS kept zooming in. "I mean, it's very pretty, don't get me wrong, but I'm not sure what I'd be able to find there." 

The blue and the purple sides of the puzzle seemed to catch more light, turning the gold into a deep turquoise, a purple-gold like you'd see in the heart of a wildflower, and she remembered the sight of the whole thing unfolded, like a rainbow accordion. Her hearts gave a little twisting thump, and she sighed, and ran the pads of her fingers over the smooth wooden sides. "Well," she said, "I suppose another stop can't hurt, can it?" 

* * * 

The planet of Perahk had been a volcanic nightmare of a place, several thousand years ago. She'd gone there with Sarah Jane once, to roast marshmallows and admire the ruddy glow of the lava, when she'd had curly white hair and wore an opera cape. 

Of course, it had calmed itself down, as all people do as they grow past the age of tantrums, and the volcanic soil had proven itself a fertile ground for every kind of flower a person could think of, and other ones besides. 

The Doctor wasn’t entirely sure which flowers were native, and which had been planted here by visitors. Word of the ludicrous richness of the soil led people to come and see, and things grew, they prospered, they flowered in new colors that people hadn’t dreamed of, crossbred with plants from other planets, other galaxies.

It was the kind of beauty that made the Doctor’s chest hurt, and she let herself drown in the bright colors, in the sweet scents and the soft petals raining down as she walked through a grove of trees. The puzzle box was in her pocket, and when she glanced down, she saw bright color coming out of her pocket. She drew it out, and it was like a mini aurora in her hand. The colors grew brighter as she walked under the great trees, towards the center of the grove.

The flowers growing on the tree had once been pink magnolias, who knew how many generations ago. They were blue now, blue with splotches of purple and great yellow stamens. They were still faintly waxy like magnolia petals, though, and they stuck in the Doctor's hair as they fell down like a warm, sweet snow.

The Doctor tilted her head back, and she looked up through the branches. It was mostly clear today, and the white clouds gently scudded across a sky the same color as the lavender growing in the meadow nearby. The dark wood of the puzzle box kept shifting, blue to purple to red to orange to yellow to green to blue to green to yellow... She stared at it, transfixed, and as she walked deeper into the grove, the colors began to shift faster, until it almost hurt to look at.

She had come here with Peri, the last time she'd been a blond, and her companion had spent almost six hours dashing from place to place and exclaiming over... well, all of it. The Doctor had sat under a tree and eaten a sandwich, then had a truly wonderful nap and woke up covered in hybrid cherry petals. 

The Doctor turned her face up, and the shadows danced across her face like waves on a beach, the sweet smell of flowers strong in her sinuses, mingling together in a sweet cacophony. The puzzle box gave a little _ding_ every time a petal landed on it, and the Doctor held the wood side up, towards the rain of them. There were more little _dings_ , and the lights seemed to be getting even brighter.

"Oh, did I miss it?" A familiar voice said, and the Doctor turned to see River walking over from a different path in a dress printed with great yellow sunflowers. "What are we up to?"

The Doctor didn't say anything, just held the puzzle box up. 

River smiled, and it went all the way to her eyes. There were flower petals in her hair, and the Doctor plucked one out, pressing it against the puzzle box. It seemed like the thing to do, honestly. This petal was a deep, dark red - the same red as River's lipstick. When the petal touched the puzzle, the wood began to glow red, emitting light like a star. 

"Look at that," River said, as she shook her head and more petals dropped out of her curls. "I've been looking forward to seeing that one."

"So you didn't know about it either?" The Doctor looked at River sidelong, one eyebrow up. "I've been going on this wild goose chase because you sent me on it, y'know."

"It's hardly a goose chase, if you know what you're looking for," River said, and she wrapped an around the Doctor's waist, rested her cheek against the Doctor's shoulder. "D'you remember the first time we came here?"

"This is the first time, for me," the Doctor said. "Not here, obviously, been here before. But the first time I've been here with you." She laced their fingers together, and there was a flower petal pressed between their palms. When they pulled apart, there was a little purple stain in the Doctor's lifeline, into the loveline, and the whimsy of the image made her grin. 

"There are rose trees, back there," River said, pointing over her shoulder with a thumb. "I've a bottle of champagne and a proper picnic spread down that way, if you'd like?"

"That sounds absolutely delightful," the Doctor said, and she picked another red petal out of River's hair. "You can tell me where in the plot _you're_ at."

"That would be cheating," River said, but she didn't sound especially shocked as the two of them made their way through the great hallway of the trees, the petals gently falling around them as the wind buffeted the branches.

* * *

It was Yaz of all people who pointed out the next time the puzzle box reacted. 

"Doctor," the other woman said, "is there a reason the TARDIS is beeping with that little box on the console?"

The Doctor, who had been digging through a wall panel, frowned. "Hm?" 

It had been a quiet strip of time. At least, quiet in terms of the puzzle box. The Doctor had been involved in three revolutions, two space rescues, and one party that had led to a revolution and then a space rescue. So generally normal on the Doctor's end. The box had sat there, blue and purple and red, and it had seemed perfectly content on its little shelf. 

The Doctor may have been imagining things, but it felt a bit like the thing was taking in the scenery, biding its time. Knowing River's penchant for exciting artifacts, it very well might have been. 

"The box," Yaz said, indicating the console over her shoulder. "With the colorful sides? It started chiming, and the TARDIS is chiming back."

"Oh," said the Doctor, sitting back on her heels and wiping her greasy hands on a nearby rag. "Finally felt like doin' somethin', then."

"Does that mean the TARDIS is going to explode or something?" Yaz looked faintly nervous, and the Doctor gave the human her most reassuring smile. 

Yaz didn't look reassured, which took some of the fun out of it. 

"Not gonna explode at all, don't worry," the Doctor told Yaz, and she stood up, wincing. "I swear, my last set of knees were more cooperative." 

Yaz snorted, but she was starting to grin again. "You talk about your body the way my granddad used to talk about his car," she told the Doctor. 

"Sometimes I feel like a car," the Doctor said, "with too much mileage. Need to go in, get me oil changed, maybe some new wheels." She paused, wrinkled her nose. "Think I might've lost the metaphor a bit there." 

"Little bit, yeah," Yaz agreed. "Or at least, it went some weird places."

"What's the point of a metaphor, if you don't get to go interesting places with it? Gotta ride it into the ground!"

"And we're back to the car metaphors," Yaz said.

"Circles and roundabouts," the Doctor said, and then she paused. "That one didn't work as well, did it?" 

"Good try," Yaz said, giving the Doctor a conciliatory pat on the shoulder. 

"It's all I can ask for, really," the Doctor said, and she made her way towards the console room again, to see the puzzle box and the TARDIS exchanging tones back and forth with each other. There was a blinking dot on the map, right over the planet of Yomglaze. 

_Hm_.   
* * *

After the Fam had been seen back in Sheffield, the Doctor went to Yomglaze. She let the TARDIS choose the location, since her old friend had been the one to triangulate it. "I think that you're doing half the hard work at this point," she told the TARDIS, stroking the console. "Do you miss her too?" 

A slow, low beep.

The Doctor didn't really try to figure out what the relationship between the TARDIS and River was, since... well. Sometimes she knew not to stick her nose into other people's relationships. Especially the kind of complicated relationships that River cultivated. 

"Well," said the Doctor, and she ran her fingers along the shiny purple surface of the puzzle box, where more light reflected, like an amethyst threaded with gold. "I can't blame you." Her voice went a little quieter. "I miss her too." 

* * *

The planet of Yomglaze was a fairly popular tourist destination. The sand on the beaches was not made from traditional rocks, but from the gemstones, which formed deep on the seafloor, only to be battered by the waves into sand. There was naturally occurring sea glass as well (which wasn't technically sea glass, but actually the shells of a specific kind of mollusk, but still), and the beaches glittered like a smashed stained glass window. 

When the TARDIS door opened for her, the Doctor blinked up into the candyfloss clouds. The sun was starting to set, and it was turning the clouds the color of cherry blossoms. Of course, since she was at the beach, she couldn't just keep her shoes on - she kicked her boots off, pulled off her socks. At this point in time, there weren't any sentient life forms on the land, so she didn't even have to worry about being yelled at for trespassing. 

Not that she ever worried about that kind of thing, but not having to not worry about it was always nice. 

The Doctor shrugged out of her coat, rolled up her sleeves. The air was warm on her exposed skin, and it smelled like salt and like the warm sand. It crunched a little bit beneath her soles as she walked towards the shoreline, rummaging in the pocket of her trousers. 

The puzzle box was cold now, and it seemed to get colder the closer she got to the water. It was a bit like holding a cold drink can after taking it out of the fridge at the shop, the chill sinking into the delicate skin of her palms. 

"You are a brilliant piece of technology," the Doctor told the puzzle box, and then she made an inelegant noise as the cold water got her right in the shins. At least she didn't have to roll her cuffs up. She'd never been particularly good at that. 

The little bits of sea glass and jeweled sand shifted under her feet, and the undertow tugged her forward. She held the puzzle carefully in one hand, and she paused before wading deeper. All the other times she'd gotten to this point in the puzzle, where she'd nearly solved it, River had shown up in a flash of light and curls, looking utterly sure of herself and put together. 

She didn't want her wife to miss the next part, did she?

So the Doctor went back towards the TARDIS, and she sat in the doorway, legs stretched in front of her, to watch the stars slowly start to come out, twinkling like jewels themselves up in the velvet.

* * *

River arrived on the shore when the smaller moon was almost all the way in the sky, and the bigger moon was beginning to rise. There was a flash, and there she was, in old jeans and a button down flannel shirt. She had a rucksack over her shoulder, and her hair was tied back. 

"Hello, sweetie," she said, and she looked faintly flustered. "Would you believe I've been going up and down along the timeline to find you?"

"Does sound like you, yeah," said the Doctor, and she stood up, putting her book down. Her knees complained, but she ignored them, stretching with her arms behind her head and her back arching. "Are you going to give me any idea how you found this place?"

"You told me to meet you here," River said, then frowned. "Tell me, I suppose," she added. "Sorry. Spoilers. Sort of."

The Doctor shrugged. "What's a little bit of muddling of the timeline between lovers?" She held a hand out, and River took it. 

"I'm still getting used to you looking like this," she told the Doctor, their fingers lacing together. "Being the same height is novel." 

"You were a little taller than me, a while ago," the Doctor pointed out. "When I were still traveling with Ace." 

River cupped the Doctor's face, and she pressed their foreheads together. They fit almost perfectly together, and her hair had come out of its ponytail, and was like a curtain around them. The Doctor's hearts were beating very loudly in her ears, and it seemed to match the beat of the waves. The puzzle box was cold against her thigh, and River's breath was very warm as it gusted across her face.

The kiss was sweet, and the Doctor drowned in it, fingers hooked into the belt loops of River’s jeans. When they pulled apart, River rubbed their noses together, and she sighed. "I missed you, sweetie," she said, and her voice was quiet. "Was a bit of a shock, the first time, but being blond suits you."

"Thanks," the Doctor said, her cheeks turning red. She wasn't entirely sure how to respond to the compliment, but it made her chest tight. 

"D'you have the box?" River let go of the Doctor, leaning down to unlace her boots and pull her socks off, then roll the cuffs of her trousers up around her knees. She unbuttoned her flannel shirt, and dropped it onto the sand beside her, leaving her bare arms to glow in the moonlight. 

"Yep," the Doctor said, digging it out of her pocket. The light reflected off of the blue, the purple, and the red, and River's face opened like a rose. 

"So you've gotten the sides open yourself, then?" River bent down, digging through her rucksack. There was a cacophony of rattling and clanking, and then River was holding up her own puzzle box, the wood dark and reflecting the moons. It only had two sides bared, one the deep orange of a freshly cut topaz and smooth as glass, the other the shining yellow of sunlight filtering through honey, with a glossy sheen. 

"I've gotten a bit farther, yeah," said the Doctor. "Although isn't it _your_ puzzle box in the first place?" An idea was beginning to form in the back of her head, and she resisted the urge to rub her temples. "Or... let me guess. Spoilers?"

River winked at her, and she grinned. "Took the words right out of my mouth she said, then; "I'm a bit stuck." She looked faintly sheepish, which wasn't exactly a common look for her. "I've been a bit busy, what with... one thing and another." She made an expansive hand gesture, which didn't explain anything at all, but this didn't feel like the time for that discussion. She dropped the puzzle back in her rucksack, and then she held her open hand out to the Doctor. 

"I've got faith that you'll figure it out," said the Doctor, and she laced her fingers through River's. "Anyway, I'm about to give you a freebie."

"Never could resist a freebie, that is true," River agreed. She squeezed the Doctor's fingers, her thumb stroking across the back of the Doctor's hand, and the Doctor's arms were breaking out in goosebumps that traveled up towards the back of her neck. 

The two of them walked towards the shore on the moonlit sands, and the Doctor kept catching River shooting her faintly furtive glances. 

"Are you really okay with my new face?" There was a note of anxiety threading through the Doctor's voice, and she wished she could pick it out like a loose thread in a tapestry. "I mean, even if you weren't, there's not much that I could do about it but -"

River stopped, and she took the Doctor's face in her hands. She kissed the Doctor, and it was a sweet, deep kiss that left the Doctor's hearts beating and her head fuzzy. "I like the new face," she told the Doctor, and her voice resonated through her chest, vibrated against the Doctor's own chest. "Just getting used to it." 

"'s'how I've been feeling," the Doctor admitted. The hand not holding the puzzle was clutching at River's shirt, and she was shaking, just a bit. "Gettin' used to... all of it."

"It suits you," said River, "although I suppose you've always suited yourself, haven't you?"

"It'd be hard for me to do otherwise," the Doctor said, "although I'm sure I'd manage eventually." 

"You can do anything you set your mind to," River agreed. 

"But," the Doctor said, pulling back, "I want to see what happens next!"

"I sometimes think that's the main driving factor behind your personality," River said dryly, then; " _fuck_ that's cold!" 

The Doctor grinned, as the cold water hit her right in the shins, and she laughed, the whooping echoing across the wide flatness of the ocean. The box in her hand was getting colder as she moved forward, and she shivered, as the water hit the hem of her trousers. 

"I'm going to need to wash these," River said, although she didn't seem put out by it. They waded further forward, until the water was up to their waists, and then the Doctor paused. The water was colder, and the coldness lapping at her navel matched the coldness in her hand. 

The Doctor ran her fingers along the edges of the puzzle box, and found it to be sealed as tight as a drum. The thing was well made enough that it probably wouldn't sustain any water damage. Or maybe she was wrong, and... well. 

Following her instincts hadn't done her wrong yet, had it?

... Actually, yes, multiple times, but this wasn't the time to worry about that. 

She held the little puzzle box under the water, and there was a muffled little _ding_. The box was cold, and when she pulled it up, the wood was turning the rich green of shaded moss. It was, in fact, the color of the deepest ocean on this planet. 

“Look at that,” River said, and she sounded enchanted. “That’s absolutely marvelous, you know that?” 

There were only two panels left to be bared now, and the Doctor leaned against River, holding the puzzle box up. “Can I get a clue as to how to solve the other ones?” 

“That would be telling,” said River. The two of them were making their way towards the shore, and then a wave hit at the wrong moment, and then the two of them were tripping over themselves and landing on the sand in a whole tangle of limbs, laughing.

The Doctor was _cackling_ when she got hit in the chest with a wave, and River was laughing as well, her hair pasted down by the salt water. She shoved the puzzle box into a pocket, awkwardly, and she clung to River's hand as the water hit them in the chest, the shoulders. 

River’s head was thrown back, and the moonlight was so _bright_ , shiny and bright. It was like a perfect moment, captured like a diamond in the heart of a star. There was salt in her hair and her toes were cold, and it was so perfect that it made her chest ache. 

Her life was very long, and sometimes it was very sad, but there were always these moments - these tiny, perfect little moments that she held on to tightly, and would never let go. 

* * *

The TARDIS and the puzzle box went quiet for a little bit after that. The Doctor ran into River in the middle of a bank robbery (she still wasn't entirely clear as to who was robbing what, but they'd gotten out in one piece, more or less, although the Doctor had needed to sew a bullet hole closed on her coat). This River didn't know about the puzzle box (or at least didn't say anything when she saw it sitting on the TARDIS console), and the two of them had gone off for a lovely evening on Alewrinpo. 

And now the Doctor had the puzzle box in her pocket, and was walking through the Market. The place didn't have a name, or at least, the Doctor didn't remember it. She remembered having some of the best raisin challah she'd ever tasted, and she'd been having the craving. 

She wasn't expecting to see River at a stall selling blown glass figures. She was wearing an emerald green dress and a trench coat, her hair a windblown mass around her face. She was smiling, and the light was gilding her like a religious relic.

"River," the Doctor said, and her whole face was breaking into a grin.

River turned to look at her, and she was looking at the Doctor cautiously, no recognition in her face. "Have we met?"

"It's me," said the Doctor, and then thought _oh no_.

River kept frowning. She was holding a small blown glass octopus, and she was looking at the Doctor as if she was contemplating whether to throw it. 

_In for a lamb, in for a mountain goat_ , gibbered some part of the Doctor's mind that seemed to be degenerating the way it always did when she sensed the beginning of a paradox. 

"It's me," the Doctor said, and she took another step closer, so that they were looking directly into each other's eyes. 

River frowned, leaning closer, until their noses were almost touching. "Doctor?" Her voice was very quiet.

"It's me," the Doctor agreed. "New me. Well, same old me, obviously, I'm always me, but then we get into a bit of a ship of Theseus sort of situation, since -"

River covered the Doctor's mouth with one hand, still staring into the Doctor's eyes. "What's my mother's name?"

"Amy Pond," the Doctor said, her voice muffled by the meat and bone and sinew of River's palm. 

"And my father's?" 

"Rory Williams." 

She asked a few more questions, and the Doctor answered them. She was on her fifth question when the stall owner cleared their throat.

"As touching as this reunion is," they said, "if you're not buying anything, please go."

The Doctor shoved a piece of money (was it the right money? She wasn't sure) at the stall owner, and then made her way out of the mess of people, towards one of the little outdoor cafes. She was holding River's hand, and River was clinging very tightly to her fingers. 

She glanced over at her wife, and the look that River was shooting her was making her blush, although she wasn't sure why. "I know it's different," she said, and she cleared her throat as they both sat down in the shadow of a big purple umbrella. 

River rested her chin on her hand, looking at the Doctor and tilting her head to the side. "What made you decide to be a woman this time?" She was still holding the octopus.

The Doctor let go of River's hand to take a drink of the water that was put in front of her. "I didn't really... decide," she said. "It just sorta... happened. Seemed to be the right time for it." She shrugged, looking faintly embarrassed. 

"It suits you," River said, and she was grinning now. "I missed you, my love," she said. "What have you been up to?"

"Oh, y'know, this 'n that," the Doctor said, shifting.

The puzzle box in her pocket chimed, and the Doctor jumped, then reached in, fishing it out.

River stared at the puzzle box, entranced, her eyes wide. "What is _that_?" She gestured for the Doctor to hand it over. 

The Doctor did so, watching as River felt along the smooth planes. The box was still chiming, like a crystal goblet being struck with a fingernail, and it blended in with the sounds of the crowd all around them. River set the box down on the table, one of the wooden sides pointing up towards the sky. Almost on a whim, she set the octopus on top of it. 

The box gave a deeper chime, and the wood was beginning to turn yellow, that same yellow the Doctor remembered from before. 

"Oh," said River, and she sounded surprised. "How'd it do _that_?" 

“Haven’t the foggiest,” the Doctor said.

River took the octopus off of the puzzle box, setting it on the glass table. Her palm was pressed against the remaining dark wood spot, and then there was another chime, and the whole thing was opening up like a flower, the dark wood turning a bright, cheerful orange.

“So that’s how it’s done,” the Doctor said, and she reached out herself, because the corners of the puzzle box seemed to be getting looser.

The whole thing accordioned out, and there was that music that had captured her interest the first time. _It must be River’s fingers_ , the Doctor thought, _but only done at a certain spot. Or is it with a certain temperature?_

Where had the thing _come_ from? Where had River found it? Or maybe… where had _she_ found it, to give to River to give to her to… 

“You’re frowning,” River said. “What’s wrong?”

“Giving myself a right headache,” the Doctor said, and she carefully folded the puzzle box back up. “You still have your vortex manipulator, right?”

“Never go anyplace without it,” River confirmed. 

“Would you be willing to do me a favor?” The Doctor drummed her fingers on the table. The puzzle box was once again just a wooden box, the dark wood reflecting the suns back at her. 

“Anything for you, love,” River said, then; “almost anything for you.” 

“This is going to… somehow end up in a Judoon prison ship that I was on. And I need you to make sure that I get it.” She gave River the coordinates, and watched her wife disappear, leaving a lingering smell of ozone.

River came back several minutes later, looking ruffled and holding the puzzle box herself. 

The Doctor frowned. “Weren’t you supposed to have given that to past me?” She saw the smudge in River’s lipstick, and her hearts beat a little faster. _She just kissed me. Past me._

“I did,” said RIver. “But I took the liberty of finding it again. Don’t want to leave you all the fun of solving it again.”

She held up the now completely wooden puzzle box, and the Doctor frowned. “Hang on,” she said, “how’d that work?”

River winked at her, and stuck the puzzle box into the pocket of her trench coat. “Spoilers,” she said, and she leaned forward and kissed the Doctor. 

The Doctor kissed her back, and she pressed her forehead against River’s, rubbed their noses together 

“So,” River said, “are you going to give me any hints on how to solve this?”

“Well,” said the Doctor, “that would be cheating.” 

River wrinkled her nose, but she was smiling as she leaned back in her chair, the sunlight catching the line of her nose to her forehead, and the Doctor’s hearts sang like the birds perched on the lampposts. 

They would have to part ways soon, because that was the way they always were. But they had… now. The important part was to remember to enjoy it, and the Doctor would do her damndest to do so.


End file.
